--- zzzz-none-000/linux-3.10.107/drivers/mtd/maps/plat-ram.c	2017-06-27 09:49:32.000000000 +0000
+++ vr9-7490-729/linux-3.10.107/drivers/mtd/maps/plat-ram.c	2021-11-10 11:53:55.000000000 +0000
@@ -115,6 +115,33 @@
 	return 0;
 }
 
+static void debug_print_memmaps(struct resource *root, int level)
+{
+	int i;
+	char prefix[30]; 
+
+	for (i = 0; i < level * 3; i++) {
+		prefix[i] = ' ';
+	}
+
+	prefix[i] = 0;
+
+	printk("%s   [%d]-----------\n", prefix, level);
+	printk("%s   name=%s \n", prefix, root->name);
+	printk("%s   start=0x%08x \n", prefix, (unsigned int)root->start);
+	printk("%s   end=0x%08x \n", prefix, (unsigned int)root->end);
+	printk("%s   flags=%#lx \n", prefix, (long unsigned int)root->flags);
+	printk("%s   ------------\n", prefix);
+
+	if (root->child) {
+		debug_print_memmaps(root->child, level + 1);
+	}
+
+	if (root->sibling) {
+		debug_print_memmaps(root->sibling, level);
+	}
+}
+
 /* platram_probe
  *
  * called from device drive system when a device matching our
@@ -128,6 +155,7 @@
 	struct resource *res;
 	int err = 0;
 
+	printk("[%s] %d\n ", __func__, __LINE__);
 	dev_dbg(&pdev->dev, "probe entered\n");
 
 	if (pdev->dev.platform_data == NULL) {
@@ -173,9 +201,12 @@
 
 	/* register our usage of the memory area */
 
+	debug_print_memmaps(&iomem_resource, 0);
+
 	info->area = request_mem_region(res->start, info->map.size, pdev->name);
 	if (info->area == NULL) {
 		dev_err(&pdev->dev, "failed to request memory region\n");
+		debug_print_memmaps(&iomem_resource, 0);
 		err = -EIO;
 		goto exit_free;
 	}
@@ -183,6 +214,9 @@
 	/* remap the memory area */
 
 	info->map.virt = ioremap(res->start, info->map.size);
+	printk("[%s] ioremap start=%#x, virt=%#x \n",
+	       __func__, (unsigned int)res->start,
+	       (unsigned int)info->map.virt);
 	dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
 
 	if (info->map.virt == NULL) {